Loretta J. Mikitzel1 and Peter K. Scott1
(Partner: New Brunswick Potato Agency)
Abstract: In 1999 at Hartland, NB, a trial was conducted to evaluate the effectiveness of the various seed treatments available to potato growers in controlling seed piece decay. Potato (Solanum tuberosum 'Shepody') seedpieces were dusted with thiophanate methyl (Easeout), mancozeb (Tuberseal, Clean Crop and Dithane), lime, metiram (Polyram 16), fludioxinil (Maxim), or mancozeb + thiophanate methyl (50/50 and 75/25 Tuberseal/Easeout) the day before planting. Control seed pieces were not dusted. At planting, soil temperature was high, plants emerged rapidly, and few seed pieces decayed. In general, very few differences were observed between the various seedpiece treatments used. Initially, seed treated with Maxim emerged slower (P<0.05) and seed treated with the Tuberseal + Easeout mixtures emerged faster (P<0.05) than the control. These differences disappeared by 21 days after planting. There were no statistical differences in stems per plant, tubers per plant or total yield between seed treatments tested and the control. Total yield ranged from 315 cwt/acre (Maxim) to 352 cwt/acre (75% Tuberseal/ 25%Easeout mixture). For all treatments, marketable yields accounted for 92% of total yield. Because temperature and soil conditions early in the 1999 season were conducive to rapid plant growth and uniform emergence, few advantages to seed treatment were found.
1Potato and Horticulture Branch, NBDARD, Wicklow, NB